ruby/rjit_c.c

513 строки
18 KiB
C

/**********************************************************************
rjit_c.c - C helpers for RJIT
Copyright (C) 2017 Takashi Kokubun <k0kubun@ruby-lang.org>.
**********************************************************************/
#include "rjit.h" // defines USE_RJIT
#if USE_RJIT
#include "rjit_c.h"
#include "include/ruby/assert.h"
#include "include/ruby/debug.h"
#include "internal.h"
#include "internal/compile.h"
#include "internal/fixnum.h"
#include "internal/hash.h"
#include "internal/sanitizers.h"
#include "internal/gc.h"
#include "yjit.h"
#include "vm_insnhelper.h"
#include "probes.h"
#include "probes_helper.h"
#include "insns.inc"
#include "insns_info.inc"
// For mmapp(), sysconf()
#ifndef _WIN32
#include <unistd.h>
#include <sys/mman.h>
#endif
#include <errno.h>
#if defined(MAP_FIXED_NOREPLACE) && defined(_SC_PAGESIZE)
// Align the current write position to a multiple of bytes
static uint8_t *
align_ptr(uint8_t *ptr, uint32_t multiple)
{
// Compute the pointer modulo the given alignment boundary
uint32_t rem = ((uint32_t)(uintptr_t)ptr) % multiple;
// If the pointer is already aligned, stop
if (rem == 0)
return ptr;
// Pad the pointer by the necessary amount to align it
uint32_t pad = multiple - rem;
return ptr + pad;
}
#endif
// Address space reservation. Memory pages are mapped on an as needed basis.
// See the Rust mm module for details.
static uint8_t *
rjit_reserve_addr_space(uint32_t mem_size)
{
#ifndef _WIN32
uint8_t *mem_block;
// On Linux
#if defined(MAP_FIXED_NOREPLACE) && defined(_SC_PAGESIZE)
uint32_t const page_size = (uint32_t)sysconf(_SC_PAGESIZE);
uint8_t *const cfunc_sample_addr = (void *)&rjit_reserve_addr_space;
uint8_t *const probe_region_end = cfunc_sample_addr + INT32_MAX;
// Align the requested address to page size
uint8_t *req_addr = align_ptr(cfunc_sample_addr, page_size);
// Probe for addresses close to this function using MAP_FIXED_NOREPLACE
// to improve odds of being in range for 32-bit relative call instructions.
do {
mem_block = mmap(
req_addr,
mem_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE,
-1,
0
);
// If we succeeded, stop
if (mem_block != MAP_FAILED) {
break;
}
// +4MB
req_addr += 4 * 1024 * 1024;
} while (req_addr < probe_region_end);
// On MacOS and other platforms
#else
// Try to map a chunk of memory as executable
mem_block = mmap(
(void *)rjit_reserve_addr_space,
mem_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS,
-1,
0
);
#endif
// Fallback
if (mem_block == MAP_FAILED) {
// Try again without the address hint (e.g., valgrind)
mem_block = mmap(
NULL,
mem_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS,
-1,
0
);
}
// Check that the memory mapping was successful
if (mem_block == MAP_FAILED) {
perror("ruby: yjit: mmap:");
if(errno == ENOMEM) {
// No crash report if it's only insufficient memory
exit(EXIT_FAILURE);
}
rb_bug("mmap failed");
}
return mem_block;
#else
// Windows not supported for now
return NULL;
#endif
}
static VALUE
mprotect_write(rb_execution_context_t *ec, VALUE self, VALUE rb_mem_block, VALUE rb_mem_size)
{
void *mem_block = (void *)NUM2SIZET(rb_mem_block);
uint32_t mem_size = NUM2UINT(rb_mem_size);
return RBOOL(mprotect(mem_block, mem_size, PROT_READ | PROT_WRITE) == 0);
}
static VALUE
mprotect_exec(rb_execution_context_t *ec, VALUE self, VALUE rb_mem_block, VALUE rb_mem_size)
{
void *mem_block = (void *)NUM2SIZET(rb_mem_block);
uint32_t mem_size = NUM2UINT(rb_mem_size);
if (mem_size == 0) return Qfalse; // Some platforms return an error for mem_size 0.
if (mprotect(mem_block, mem_size, PROT_READ | PROT_EXEC)) {
rb_bug("Couldn't make JIT page (%p, %lu bytes) executable, errno: %s\n",
mem_block, (unsigned long)mem_size, strerror(errno));
}
return Qtrue;
}
static VALUE
rjit_optimized_call(VALUE *recv, rb_execution_context_t *ec, int argc, VALUE *argv, int kw_splat, VALUE block_handler)
{
rb_proc_t *proc;
GetProcPtr(recv, proc);
return rb_vm_invoke_proc(ec, proc, argc, argv, kw_splat, block_handler);
}
static VALUE
rjit_str_neq_internal(VALUE str1, VALUE str2)
{
return rb_str_eql_internal(str1, str2) == Qtrue ? Qfalse : Qtrue;
}
static VALUE
rjit_str_simple_append(VALUE str1, VALUE str2)
{
return rb_str_cat(str1, RSTRING_PTR(str2), RSTRING_LEN(str2));
}
// The code we generate in gen_send_cfunc() doesn't fire the c_return TracePoint event
// like the interpreter. When tracing for c_return is enabled, we patch the code after
// the C method return to call into this to fire the event.
static void
rjit_full_cfunc_return(rb_execution_context_t *ec, VALUE return_value)
{
rb_control_frame_t *cfp = ec->cfp;
RUBY_ASSERT_ALWAYS(cfp == GET_EC()->cfp);
const rb_callable_method_entry_t *me = rb_vm_frame_method_entry(cfp);
RUBY_ASSERT_ALWAYS(RUBYVM_CFUNC_FRAME_P(cfp));
RUBY_ASSERT_ALWAYS(me->def->type == VM_METHOD_TYPE_CFUNC);
// CHECK_CFP_CONSISTENCY("full_cfunc_return"); TODO revive this
// Pop the C func's frame and fire the c_return TracePoint event
// Note that this is the same order as vm_call_cfunc_with_frame().
rb_vm_pop_frame(ec);
EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, cfp->self, me->def->original_id, me->called_id, me->owner, return_value);
// Note, this deviates from the interpreter in that users need to enable
// a c_return TracePoint for this DTrace hook to work. A reasonable change
// since the Ruby return event works this way as well.
RUBY_DTRACE_CMETHOD_RETURN_HOOK(ec, me->owner, me->def->original_id);
// Push return value into the caller's stack. We know that it's a frame that
// uses cfp->sp because we are patching a call done with gen_send_cfunc().
ec->cfp->sp[0] = return_value;
ec->cfp->sp++;
}
static rb_proc_t *
rjit_get_proc_ptr(VALUE procv)
{
rb_proc_t *proc;
GetProcPtr(procv, proc);
return proc;
}
// Use the same buffer size as Stackprof.
#define BUFF_LEN 2048
extern VALUE rb_rjit_raw_samples;
extern VALUE rb_rjit_line_samples;
static void
rjit_record_exit_stack(const VALUE *exit_pc)
{
// Let Primitive.rjit_stop_stats stop this
if (!rb_rjit_call_p) return;
// Get the opcode from the encoded insn handler at this PC
int insn = rb_vm_insn_addr2opcode((void *)*exit_pc);
// Create 2 array buffers to be used to collect frames and lines.
VALUE frames_buffer[BUFF_LEN] = { 0 };
int lines_buffer[BUFF_LEN] = { 0 };
// Records call frame and line information for each method entry into two
// temporary buffers. Returns the number of times we added to the buffer (ie
// the length of the stack).
//
// Call frame info is stored in the frames_buffer, line number information
// in the lines_buffer. The first argument is the start point and the second
// argument is the buffer limit, set at 2048.
int stack_length = rb_profile_frames(0, BUFF_LEN, frames_buffer, lines_buffer);
int samples_length = stack_length + 3; // 3: length, insn, count
// If yjit_raw_samples is less than or equal to the current length of the samples
// we might have seen this stack trace previously.
int prev_stack_len_index = (int)RARRAY_LEN(rb_rjit_raw_samples) - samples_length;
VALUE prev_stack_len_obj;
if (RARRAY_LEN(rb_rjit_raw_samples) >= samples_length && FIXNUM_P(prev_stack_len_obj = RARRAY_AREF(rb_rjit_raw_samples, prev_stack_len_index))) {
int prev_stack_len = NUM2INT(prev_stack_len_obj);
int idx = stack_length - 1;
int prev_frame_idx = 0;
bool seen_already = true;
// If the previous stack length and current stack length are equal,
// loop and compare the current frame to the previous frame. If they are
// not equal, set seen_already to false and break out of the loop.
if (prev_stack_len == stack_length) {
while (idx >= 0) {
VALUE current_frame = frames_buffer[idx];
VALUE prev_frame = RARRAY_AREF(rb_rjit_raw_samples, prev_stack_len_index + prev_frame_idx + 1);
// If the current frame and previous frame are not equal, set
// seen_already to false and break out of the loop.
if (current_frame != prev_frame) {
seen_already = false;
break;
}
idx--;
prev_frame_idx++;
}
// If we know we've seen this stack before, increment the counter by 1.
if (seen_already) {
int prev_idx = (int)RARRAY_LEN(rb_rjit_raw_samples) - 1;
int prev_count = NUM2INT(RARRAY_AREF(rb_rjit_raw_samples, prev_idx));
int new_count = prev_count + 1;
rb_ary_store(rb_rjit_raw_samples, prev_idx, INT2NUM(new_count));
rb_ary_store(rb_rjit_line_samples, prev_idx, INT2NUM(new_count));
return;
}
}
}
rb_ary_push(rb_rjit_raw_samples, INT2NUM(stack_length));
rb_ary_push(rb_rjit_line_samples, INT2NUM(stack_length));
int idx = stack_length - 1;
while (idx >= 0) {
VALUE frame = frames_buffer[idx];
int line = lines_buffer[idx];
rb_ary_push(rb_rjit_raw_samples, frame);
rb_ary_push(rb_rjit_line_samples, INT2NUM(line));
idx--;
}
// Push the insn value into the yjit_raw_samples Vec.
rb_ary_push(rb_rjit_raw_samples, INT2NUM(insn));
// Push the current line onto the yjit_line_samples Vec. This
// points to the line in insns.def.
int line = (int)RARRAY_LEN(rb_rjit_line_samples) - 1;
rb_ary_push(rb_rjit_line_samples, INT2NUM(line));
// Push number of times seen onto the stack, which is 1
// because it's the first time we've seen it.
rb_ary_push(rb_rjit_raw_samples, INT2NUM(1));
rb_ary_push(rb_rjit_line_samples, INT2NUM(1));
}
// For a given raw_sample (frame), set the hash with the caller's
// name, file, and line number. Return the hash with collected frame_info.
static void
rjit_add_frame(VALUE hash, VALUE frame)
{
VALUE frame_id = SIZET2NUM(frame);
if (RTEST(rb_hash_aref(hash, frame_id))) {
return;
}
else {
VALUE frame_info = rb_hash_new();
// Full label for the frame
VALUE name = rb_profile_frame_full_label(frame);
// Absolute path of the frame from rb_iseq_realpath
VALUE file = rb_profile_frame_absolute_path(frame);
// Line number of the frame
VALUE line = rb_profile_frame_first_lineno(frame);
// If absolute path isn't available use the rb_iseq_path
if (NIL_P(file)) {
file = rb_profile_frame_path(frame);
}
rb_hash_aset(frame_info, ID2SYM(rb_intern("name")), name);
rb_hash_aset(frame_info, ID2SYM(rb_intern("file")), file);
rb_hash_aset(frame_info, ID2SYM(rb_intern("samples")), INT2NUM(0));
rb_hash_aset(frame_info, ID2SYM(rb_intern("total_samples")), INT2NUM(0));
rb_hash_aset(frame_info, ID2SYM(rb_intern("edges")), rb_hash_new());
rb_hash_aset(frame_info, ID2SYM(rb_intern("lines")), rb_hash_new());
if (line != INT2FIX(0)) {
rb_hash_aset(frame_info, ID2SYM(rb_intern("line")), line);
}
rb_hash_aset(hash, frame_id, frame_info);
}
}
static VALUE
rjit_exit_traces(void)
{
int samples_len = (int)RARRAY_LEN(rb_rjit_raw_samples);
RUBY_ASSERT(samples_len == RARRAY_LEN(rb_rjit_line_samples));
VALUE result = rb_hash_new();
VALUE raw_samples = rb_ary_new_capa(samples_len);
VALUE line_samples = rb_ary_new_capa(samples_len);
VALUE frames = rb_hash_new();
int idx = 0;
// While the index is less than samples_len, parse yjit_raw_samples and
// yjit_line_samples, then add casted values to raw_samples and line_samples array.
while (idx < samples_len) {
int num = NUM2INT(RARRAY_AREF(rb_rjit_raw_samples, idx));
int line_num = NUM2INT(RARRAY_AREF(rb_rjit_line_samples, idx));
idx++;
rb_ary_push(raw_samples, SIZET2NUM(num));
rb_ary_push(line_samples, INT2NUM(line_num));
// Loop through the length of samples_len and add data to the
// frames hash. Also push the current value onto the raw_samples
// and line_samples array respectively.
for (int o = 0; o < num; o++) {
rjit_add_frame(frames, RARRAY_AREF(rb_rjit_raw_samples, idx));
rb_ary_push(raw_samples, SIZET2NUM(RARRAY_AREF(rb_rjit_raw_samples, idx)));
rb_ary_push(line_samples, RARRAY_AREF(rb_rjit_line_samples, idx));
idx++;
}
// insn BIN and lineno
rb_ary_push(raw_samples, RARRAY_AREF(rb_rjit_raw_samples, idx));
rb_ary_push(line_samples, RARRAY_AREF(rb_rjit_line_samples, idx));
idx++;
// Number of times seen
rb_ary_push(raw_samples, RARRAY_AREF(rb_rjit_raw_samples, idx));
rb_ary_push(line_samples, RARRAY_AREF(rb_rjit_line_samples, idx));
idx++;
}
// Set add the raw_samples, line_samples, and frames to the results
// hash.
rb_hash_aset(result, ID2SYM(rb_intern("raw")), raw_samples);
rb_hash_aset(result, ID2SYM(rb_intern("lines")), line_samples);
rb_hash_aset(result, ID2SYM(rb_intern("frames")), frames);
return result;
}
// An offsetof implementation that works for unnamed struct and union.
// Multiplying 8 for compatibility with libclang's offsetof.
#define OFFSETOF(ptr, member) RB_SIZE2NUM(((char *)&ptr.member - (char*)&ptr) * 8)
#define SIZEOF(type) RB_SIZE2NUM(sizeof(type))
#define SIGNED_TYPE_P(type) RBOOL((type)(-1) < (type)(1))
// Insn side exit counters
static size_t rjit_insn_exits[VM_INSTRUCTION_SIZE] = { 0 };
// macOS: brew install capstone
// Ubuntu/Debian: apt-get install libcapstone-dev
// Fedora: dnf -y install capstone-devel
#ifdef HAVE_LIBCAPSTONE
#include <capstone/capstone.h>
#endif
// Return an array of [address, mnemonic, op_str]
static VALUE
dump_disasm(rb_execution_context_t *ec, VALUE self, VALUE from, VALUE to, VALUE test)
{
VALUE result = rb_ary_new();
#ifdef HAVE_LIBCAPSTONE
// Prepare for calling cs_disasm
static csh handle;
if (cs_open(CS_ARCH_X86, CS_MODE_64, &handle) != CS_ERR_OK) {
rb_raise(rb_eRuntimeError, "failed to make Capstone handle");
}
size_t from_addr = NUM2SIZET(from);
size_t to_addr = NUM2SIZET(to);
// Call cs_disasm and convert results to a Ruby array
cs_insn *insns;
size_t base_addr = RTEST(test) ? 0 : from_addr; // On tests, start from 0 for output stability.
size_t count = cs_disasm(handle, (const uint8_t *)from_addr, to_addr - from_addr, base_addr, 0, &insns);
for (size_t i = 0; i < count; i++) {
VALUE vals = rb_ary_new_from_args(3, LONG2NUM(insns[i].address), rb_str_new2(insns[i].mnemonic), rb_str_new2(insns[i].op_str));
rb_ary_push(result, vals);
}
// Free memory used by capstone
cs_free(insns, count);
cs_close(&handle);
#endif
return result;
}
// Same as `RubyVM::RJIT.enabled?`, but this is used before it's defined.
static VALUE
rjit_enabled_p(rb_execution_context_t *ec, VALUE self)
{
return RBOOL(rb_rjit_enabled);
}
static int
for_each_iseq_i(void *vstart, void *vend, size_t stride, void *data)
{
VALUE block = (VALUE)data;
VALUE v = (VALUE)vstart;
for (; v != (VALUE)vend; v += stride) {
void *ptr = asan_poisoned_object_p(v);
asan_unpoison_object(v, false);
if (rb_obj_is_iseq(v)) {
extern VALUE rb_rjit_iseq_new(rb_iseq_t *iseq);
rb_iseq_t *iseq = (rb_iseq_t *)v;
rb_funcall(block, rb_intern("call"), 1, rb_rjit_iseq_new(iseq));
}
asan_poison_object_if(ptr, v);
}
return 0;
}
static VALUE
rjit_for_each_iseq(rb_execution_context_t *ec, VALUE self, VALUE block)
{
rb_objspace_each_objects(for_each_iseq_i, (void *)block);
return Qnil;
}
// bindgen funcs
extern ID rb_get_symbol_id(VALUE name);
extern VALUE rb_fix_aref(VALUE fix, VALUE idx);
extern VALUE rb_str_getbyte(VALUE str, VALUE index);
extern VALUE rb_vm_concat_array(VALUE ary1, VALUE ary2st);
extern VALUE rb_vm_get_ev_const(rb_execution_context_t *ec, VALUE orig_klass, ID id, VALUE allow_nil);
extern VALUE rb_vm_getclassvariable(const rb_iseq_t *iseq, const rb_control_frame_t *cfp, ID id, ICVARC ic);
extern VALUE rb_vm_opt_newarray_min(rb_execution_context_t *ec, rb_num_t num, const VALUE *ptr);
extern VALUE rb_vm_splat_array(VALUE flag, VALUE array);
extern bool rb_simple_iseq_p(const rb_iseq_t *iseq);
extern bool rb_vm_defined(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp, rb_num_t op_type, VALUE obj, VALUE v);
extern bool rb_vm_ic_hit_p(IC ic, const VALUE *reg_ep);
extern rb_event_flag_t rb_rjit_global_events;
extern void rb_vm_setinstancevariable(const rb_iseq_t *iseq, VALUE obj, ID id, VALUE val, IVC ic);
extern VALUE rb_vm_throw(const rb_execution_context_t *ec, rb_control_frame_t *reg_cfp, rb_num_t throw_state, VALUE throwobj);
extern VALUE rb_reg_new_ary(VALUE ary, int opt);
extern void rb_vm_setclassvariable(const rb_iseq_t *iseq, const rb_control_frame_t *cfp, ID id, VALUE val, ICVARC ic);
extern VALUE rb_str_bytesize(VALUE str);
extern const rb_callable_method_entry_t *rb_callable_method_entry_or_negative(VALUE klass, ID mid);
extern VALUE rb_vm_yield_with_cfunc(rb_execution_context_t *ec, const struct rb_captured_block *captured, int argc, const VALUE *argv);
#include "rjit_c.rbinc"
#endif // USE_RJIT